TRANSACTIONS OF SECTION K. 843 



advantao-e over those who proceed by the old rule-of-thumh methods, where 

 nobody knows or cares where the waste or leakage occurs that spoils a commercial 

 product. 



The discovery by Alvarez of the bacillus which converts a sterilised decoction 

 of indigo-plant into indigo sugar and indigo white, the latter then oxidising to form 

 the valuable blue dye, whereas the sterile decoction itself, even in presence of 

 oxygen, forms no indigo, may be cited as a case in point. It remains to be decided 

 whether this bacillus alone is concerned, or whether the infusion of indican will fer- 

 ment under the action of enzymes alone derived from the leaves of the indigo plant. 

 It also remains for future investigation to determine whether the indigo bacillus is 

 the same as the pneumonia bacillus — which resembles it — and will also induce the 

 indigo fermentation, and to explain why the woad-makers of the Fens find a sale 

 for this indigo preparation among the indigo makers, as well as to clear up certain 

 mysterious ' diseases ' in the indigo-vats. Our much more extensive knowledge of 

 the diseases of beer and wine suggests the possibility of profitable bacteriological 

 investigations in several directions here. 



That certain stages in the preparation of tobacco leaves — as also in the pre- 

 paration of tea — depend on a carefully regulated fermentation, which must be 

 stopped at the right moment, or the product is impaired, or even ruined, has long 

 been known. Regarding the possible role of bacteria in the preparation of tea, 

 nothing is ascertained, Ijut, if Suchsland's investigations are confirmed, there is 

 among the many and various organisms concerned in the fermentation of West 

 Indian tobacco a bacterium which has been isolated and plays an important part. 

 It is claimed that the flavour of European-grown tobacco can be materially 

 improved by its use. I read that the process is patented, which may or may not 

 affect its value as a scientific announcement ; but in view of the increasing number 

 of researches into this subject by Behrens, Davalos, Schloesing, and others, it is 

 evidently a domain for further bacteriological investigations in a properly equipped 

 laboratory. 



Every botanist knows that flax and hemp are the bast fibres of Linurn 

 and Cannabis respectively, separated by steeping in water until the middle 

 lamella is destroyed and the fibres isolated ; but it is perhaps not so well known 

 that not every water is suitable for this ' retting ' or steeping process, and for a 

 long time this was as much a mystery as why some waters are better than others 

 for brewing. 



Only quite recently Fribes, working under Winogradsky, has isolated the 

 bacillus which accomplishes this dissolution of the middle lamella, and its 

 behaviour brings to light some very interesting details, and furnishes another of 

 those cases where the reactions of living micro-organisms can be utilised in 

 deciding questions of plant chemistry too subtlefortesting with ordinary reagents. 



You are aware that recent researches, especially those of Maquin in France 

 and of "Walter Gardiner in Cambridge, Cross and Bevan and others, have caused 

 us to discard the view that the middle lamella is composed of cellulose, and to 

 learn that it consists of pectin compounds. Now Fribes' anaerobic bacillus dis- 

 solves and destroys pectins and pectinates, but does not touch cellulose or gum, 

 and thus enables us to criticise from a new point of view the bacillus {B. Amijlo- 

 bacter) which Van Tieghem asserted to be the cause of cellulose fermentation and 

 of the retting of flax. Clearly it cannot be both, otherwise the flax-fibre would be 

 destroyed ; and we know from other facts that B. Ajnylobacter is not the cellulose 

 ferment. 



Fribes* discovery has yet to be tested with reference to other processes of 

 retting. The Indian Government have lately published a series of notes on jute 

 and other fibres, and the description of the retting of jute suggests this as a very 

 definite problem for investigation. 



I am told that a patent exists in the United States for a process whereby the 

 retting organisms may be sown and encouraged in waters otherwise unfitted for 

 the steeping of flax, &c., another indication of the keen interest taken in these 

 matters. 



It goes without saying that the steeping of skins in water in preparation for 



